fix: Index incorrectly handling file references on the local file system.

This was reported in https://github.com/daveshanley/vacuum/issues/225, it's a continuation of the issue found in https://github.com/pb33f/libopenapi/issues/37. This fix allows the full import of the file (not just a path/component) to be imported.

Signed-off-by: Dave Shanley <dave@quobix.com>

README.md

@@ -1,9 +1,10 @@
 <p align="center">
-	<img src="libopenapi-logo.png" alt="libopenapi" height="300px"/>
+	<img src="libopenapi-logo.png" alt="libopenapi" height="300px" width="450px"/>
 </p>
 
 # libopenapi - enterprise grade OpenAPI tools for golang.
 
+
 ![Pipeline](https://github.com/pb33f/libopenapi/workflows/Build/badge.svg)
 [![GoReportCard](https://goreportcard.com/badge/github.com/pb33f/libopenapi)](https://goreportcard.com/report/github.com/pb33f/libopenapi)
 [![codecov](https://codecov.io/gh/pb33f/libopenapi/branch/main/graph/badge.svg?)](https://codecov.io/gh/pb33f/libopenapi)

index/spec_index.go

@@ -1,4 +1,4 @@
-// Copyright 2022 Dave Shanley / Quobix
+// Copyright 2022-2033 Dave Shanley / Quobix
 // SPDX-License-Identifier: MIT
 
 // Package index contains an OpenAPI indexer that will very quickly scan through an OpenAPI specification (all versions)
@@ -1647,6 +1647,19 @@ func (index *SpecIndex) FindComponent(componentId string, parent *yaml.Node) *Re
 		if len(uri) == 2 {
 			return index.performExternalLookup(uri, componentId, fileLookup, parent)
 		}
+		if len(uri) == 1 {
+			// if there is no reference, second segment is empty / has no name
+			// this means there is no component to look-up and the entire file should be pulled in.
+			// to stop all the other code from breaking (that is expecting a component), let's just post-pend
+			// a hash to the end of the componentId and ensure the uri slice is as expected.
+			// described in https://github.com/pb33f/libopenapi/issues/37
+			//
+			// ^^ this same issue was re-reported in file based lookups in vacuum.
+			// more info here: https://github.com/daveshanley/vacuum/issues/225
+			componentId = fmt.Sprintf("%s#", componentId)
+			uri = append(uri, "")
+			return index.performExternalLookup(uri, componentId, fileLookup, parent)
+		}
 	}
 	return nil
 }
@@ -2080,10 +2093,6 @@ func (index *SpecIndex) lookupFileReference(ref string) (*yaml.Node, *yaml.Node,
 	// split string to remove file reference
 	uri := strings.Split(ref, "#")
 
-	if len(uri) != 2 {
-		return nil, nil, fmt.Errorf("unable to determine filename for file reference: '%s'", ref)
-	}
-
 	file := strings.ReplaceAll(uri[0], "file:", "")
 
 	var parsedRemoteDocument *yaml.Node
@@ -2106,7 +2115,12 @@ func (index *SpecIndex) lookupFileReference(ref string) (*yaml.Node, *yaml.Node,
 	}
 
 	// lookup item from reference by using a path query.
-	query := fmt.Sprintf("$%s", strings.ReplaceAll(uri[1], "/", "."))
+	var query string
+	if len(uri) >= 2 {
+		query = fmt.Sprintf("$%s", strings.ReplaceAll(uri[1], "/", "."))
+	} else {
+		query = "$"
+	}
 
 	// remove any URL encoding
 	query = strings.Replace(query, "~1", "./", 1)

index/spec_index_test.go

@@ -555,6 +555,40 @@ func TestSpecIndex_lookupRemoteReference_NoComponent(t *testing.T) {
 	assert.Nil(t, b)
 }
 
+// Discovered in issue https://github.com/daveshanley/vacuum/issues/225
+func TestSpecIndex_lookupFileReference_NoComponent(t *testing.T) {
+
+	index := new(SpecIndex)
+	_ = ioutil.WriteFile("coffee-time.yaml", []byte("time: for coffee"), 0o664)
+	defer os.Remove("coffee-time.yaml")
+
+	index.seenRemoteSources = make(map[string]*yaml.Node)
+	a, b, err := index.lookupFileReference("coffee-time.yaml")
+	assert.NoError(t, err)
+	assert.NotNil(t, a)
+	assert.NotNil(t, b)
+}
+
+func TestSpecIndex_CheckIndexDiscoversNoComponentLocalFileReference(t *testing.T) {
+
+	_ = ioutil.WriteFile("coffee-time.yaml", []byte("name: time for coffee"), 0o664)
+	defer os.Remove("coffee-time.yaml")
+
+	yml := `openapi: 3.0.3
+paths:
+  /cakes:
+    post:
+      parameters:
+        - $ref: 'coffee-time.yaml'`
+
+	var rootNode yaml.Node
+	yaml.Unmarshal([]byte(yml), &rootNode)
+
+	index := NewSpecIndex(&rootNode)
+
+	assert.NotNil(t, index.GetAllParametersFromOperations()["/cakes"]["post"]["coffee-time.yaml"].Node)
+}
+
 func TestSpecIndex_lookupRemoteReference_SeenSourceSimulation_BadJSON(t *testing.T) {
 	index := new(SpecIndex)
 	index.seenRemoteSources = make(map[string]*yaml.Node)